Method for picture decoding, decoder and storage medium

ABSTRACT

An image decoding method, a decoder and a storage medium are porovided. The method includes: receiving code stream data, and parsing the code stream data to obtain a coding tree unit corresponding to the code stream data; parsing an i-th node of i-th layer corresponding to the coding tree unit to obtain i-th state parameter and i-th flag parameter corresponding to the i-th node; performing detection processing on the i-th node according to the i-th state parameter and the i-th flag parameter to obtain an i-th detection result; acquiring a (i+1)th node of a (i+1)th layer corresponding to the coding tree unit; continuing to perform detection processing on the (i+1)th node, and traversing all the nodes corresponding to the coding tree unit until all the coding unit data corresponding to the coding tree unit is obtained; and generating a decoded image corresponding to the code stream data.

CROSS-REFERNCE TO RELATED APPLICATIONS

The application is a continuation application of PCT Application No.PCT/CN2019/083966 filed on Apr. 23, 2019, the disclosure of which ishereby incorporated by reference in its entity.

BACKGROUND

At present, a technical solution to video coding mainly refers topartitioning a space region of a picture into small blocks that are notoverlapped with each other as basic units for coding using apartitioning technology and then coding the small blocks. Commonly usedmulti-type-tree (MTT) is evolved step by step from Quadtree (QT) toQuad-Tree-Binary-Tree (QTBT) and then further in combination withTernary Tree (TT). Therefore, the only difference of QT, QTBT, and MTTis that partitioning manners for picture partitioning are different, andthe partitioning principles of the three technologies are the same.

Detailed partitioning is usually needed to be performed on each frame ofpicture during video coding to achieve a relatively good coding effect,and in addition, detailed partitioning may generate more headerinformation and repeated information representations due to a fixedpartitioning solution in an existing video coding technology, so thatthe coding efficiency is reduced.

SUMMARY

Embodiments of the application relate to the technical field of videoencoding and decoding, and particularly to a method for picturedecoding, a decoder, and a storage medium.

The embodiments of the application provide a method for picturedecoding, a decoder, and a storage medium, which may avoid excessivelydetailed block partitioning and effectively reduce the amount of headerinformation, thereby improving the coding efficiency.

The technical solutions of the embodiments of the application areimplemented as follows.

In a first aspect, a method for picture decoding is provided, which mayinclude the following operations.

Bitstream data is received, and the bitstream data is parsed to obtain aCoding Tree Unit (CTU) corresponding to the bitstream data.

An ith node of an ith layer corresponding to the CTU is parsed to obtainan ith state parameter and ith flag parameter corresponding to the ithnode, i being an integer greater than 0, the ith state parameter beingconfigured to determine whether the ith node supports refreshing, andthe ith flag parameter being configured to determine whether the ithnode enables refreshing.

Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain an ith detectionresult.

An (i+1)th node of an (i+1)th layer corresponding to the CTU is acquiredaccording to the ith detection result.

Detection processing is continued to be performed on the (i+1)th node,and all nodes corresponding to the CTU are traversed until data of allCoding Units (CUs) corresponding to the CTU is obtained.

A decoded picture corresponding to the bitstream data is generatedaccording to the all nodes and the data of all CUs.

In a second aspect, a decoder is provided. The decoder comprises aprocessor and a memory storing instructions executable by the processor.When the instructions are executed by the processor, the processor isconfigured to receive bitstream data, parse the bitstream data to obtaina Coding Tree Unit (CTU) corresponding to the bitstream data, parse anode of a layer corresponding to the CTU to determine a state parameterand a flag parameter corresponding to the node, the state parameterbeing configured to determine whether the node supports refreshing, andthe flag parameter being configured to determine whether the nodeenables refreshing, perform detection processing on the node accordingto a leaf parameter, the state parameter and the flag parameter toobtain a detection result, continue to acquire a node of a next layercorresponding to the CTU according to the detection result, continue toperform detection processing on the node of the next layer, and obtaindata of all Coding Units (CUs) corresponding to the CTU, and generate adecoded picture corresponding to the bitstream data according to thenode and the data of all Cus.

In a third aspect, a computer-readable storage medium is provided. Thecomputer-readable storage medium has stored therein a computer programwhich is applied to a decoder and is executed by a processor to performthe method for picture decoding of the above first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first schematic diagram of partitioning using QT.

FIG. 2 is a second schematic diagram of partitioning using QT.

FIG. 3 is a schematic diagram of over-partitioning.

FIG. 4 is a composition structure diagram of a video encoding system.

FIG. 5 is a composition structure diagram of a video decoding system.

FIG. 6 is an implementation flowchart of a method for picture decodingaccording to embodiments of the application.

FIG. 7 is a structure diagram of a CTU according to the conventionalart.

FIG. 8 is a structure diagram of a CTU according to embodiments of theapplication.

FIG. 9 is a first flowchart of a method for picture decoding accordingto embodiments of the application.

FIG. 10 is a second flowchart of a method for picture decoding accordingto embodiments of the application.

FIG. 11 is a schematic diagram of a state parameter and a flag parameteraccording to embodiments of the application.

FIG. 12 is a first schematic diagram of partitioning processing.

FIG. 13 is a second schematic diagram of partitioning processing.

FIG. 14 is a third schematic diagram of partitioning processing.

FIG. 15 is a fourth schematic diagram of partitioning processing.

FIG. 16 is a fifth schematic diagram of partitioning processing.

FIG. 17 is a sixth schematic diagram of partitioning processing.

FIG. 18 is a schematic diagram of a method for picture encodingaccording to embodiments of the application.

FIG. 19 is a first schematic diagram of non-overlapping partitioning.

FIG. 20 is a second schematic diagram of non-overlapping partitioning.

FIG. 21 is a first schematic diagram of overlapping partitioning.

FIG. 22 is a second schematic diagram of overlapping partitioning

FIG. 23 is a first composition structure diagram of a decoder accordingto embodiments of the application.

FIG. 24 is a second composition structure diagram of a decoder accordingto embodiments of the application.

DETAILED DESCRIPTION

The embodiments of the application provide the method for picturedecoding, the decoder, and the storage medium. The decoder receives thebitstream data, and parses the bitstream data to obtain the CTUcorresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and the all nodescorresponding to the CTU are traversed until data of all CUscorresponding to the CTU is obtained. The decoded picture correspondingto the bitstream data is generated according to the all nodes and thedata of all CUs. It can be seen that, in the embodiments of theapplication, in a process of decoding a picture in a video, afterbitstream data is received and parsed to obtain a CTU, parsingprocessing may be performed on a node of each layer corresponding to theCTU to obtain a state parameter and flag parameter corresponding to thenode of this layer, then detection processing is performed on the nodeaccording to the state parameter and the flag parameter, and thendecoding processing is performed on a node with data, to obtain all CUscorresponding to the CTU to obtain a corresponding decoded picture.Since overlapping partitioning of CUs is supported during coding, if allthe CUs, obtained by the decoder by decoding nodes with data, include atleast two regionally overlapping CUs, the decoder may perform refreshingprocessing on picture information corresponding to a background CUaccording to picture information corresponding to a refreshing CU.Therefore, over-partitioning of video pictures may be avoided,unnecessary header information may be reduced, distributed and repeatedrepresentations of data with similar features in the same region may beavoided, and the coding efficiency may further be improved.

The technical solutions in the embodiments of the application will beclearly and completely described below in combination with the drawingsin the embodiments of the application. It is to be understood that thespecific embodiments described here are adopted not to limit the relatedapplication but only to explain the application. In addition, it is alsoto be noted that, for convenient description, only parts related to theapplication are illustrated in the drawings.

Encoding a video refers to encoding the pictures one frame by one frame.Similarly, decoding a video bitstream obtained by coding compression ona video refers to decoding the bitstream of pictures one frame by oneframe. In almost all international video picture coding standards, whena frame of picture is coded, the frame of picture is required to bepartitioned into a plurality of sub pictures with M×M pixels, calledCUs, and the sub pictures are coded one by one by taking a CU as a basiccoding unit. Generally, M may be 4, 8, 16, 32, or 64. Therefore,encoding a video pictures sequence refers to sequentially encoding eachcoding unit, i.e., each CU, of each frame of picture. Decoding abitstream of a video picture sequence refers to sequentially decodingeach CU of each frame of picture to finally reconstruct the whole videopicture sequence.

For adapting to differences of contents and properties of picturecontents of each part in a frame of picture and pertinently performingmost effective coding, sizes of CUs in the frame of picture may bedifferent, some are 8×8, some are 64×64, etc. For seamlessly stitchingCUs with different sizes, a frame of picture is usually partitioned intoLargest Coding Units (LCUs) or CTUs with the completely same size of N×Npixels at first, and then each LCU is further partitioned into multipleCUs that may be the same or different in size. For example, a frame ofpicture is partitioned into LCUs with the completely same size of 64>64pixels at first, namely N=64. A certain LCU is formed by three CUs with32×32 pixels and four CUs with 16×16 pixels, and another LCU is formedby two CUs with 32×32 pixels, three CUs with 16×16 pixels, and 20 CUswith 8×8 pixels. The CU may further be partitioned into a plurality ofsub regions. The sub region includes, but not limited to, a PredictionUnit (PU) and a Transformation Unit (TU). In summary, an encoding blockor a decoding block refers to a region that is encoded or decoded in aframe of picture.

A CU is a region formed by a plurality of pixel values. A shape of theCU may a rectangle. Each CU in a frame of picture may be different inshape and size.

In H.265/High Efficiency Video Coding (HEVC), QT may be used to performnon-overlapping partitioning of CUs or coding blocks. FIG. 1 is a firstschematic diagram of partitioning using QT. As shown in FIG. 1, a frameof picture is partitioned into multiple regions with the same size byrows and columns, each region being called a CTU. A side length of a CTUmay be 128 pixels, 64 pixels, etc. Such partitioning is horizontal andvertical hard partitioning, so that the CTUs may not overlap. FIG. 2 isa second schematic diagram of partitioning using QT. As shown in FIG. 2,a CTU is progressively partitioned into multiple CUs in a QT manner.Sizes of the multiple CUs are not all the same, and there are CUs with8×8 pixels, 16×16 pixels, and CUs with 32×32 pixels. The CUs have nooverlapping regions, and all the CUs are leaf nodes obtained by QTpartitioning. Similarly, such partitioning is horizontal and verticalhard partitioning, so that the CUs obtained by partitioning any CTU maynot overlap.

In an existing H.266/Versatile Video Coding (VVC)-based video codingtechnology, BT is added based on QT to form QTBT, and a TT partitioningmanner is further added to form MTT. Various partitioning manners inMTT, such as QT partitioning, vertical BT partitioning, horizontal BTpartitioning, vertical center/both-side TT partitioning, and horizontalcenter/both-side TT partitioning, are all used on each layer in a CTU.

It can thus be seen that a present MTT solution is coherently evolvedstep by step from QT to QTBT and then in combination with TT. The onlydifference of QT, QTBT, and MTT is that partitioning manners aredifferent, and the three use the same partitioning principle of nooverlaps between CUs. That is, since all present partitioning solutionsdo not allow overlapping regions between CUs, a fixed partitioningmanner makes it necessary to perform detailed partitioning on anirregular edge of an object to achieve a relatively good video codingeffect. On the other aspect, detailed partitioning generates more headerinformation. Therefore, the coding efficiency may be reduced. With thediversification of partitioning modes, some problems of detailedpartitioning have been solved, but the problem of over-partitioningstill exists. FIG. 3 is a schematic diagram of over-partitioning. Asshown in FIG. 3, after the region at the upper edge of the ball held bythe player on the right side is partitioned and amplified, it can beseen that most of the region is a similar background flat region, andonly the top end of the ball is a content different from the otherregion in the block. For partitioning a corresponding region, a finalpartitioning result is quite detailed. It can be seen that detailedpartitioning is usually needed to be performed on each frame of picturein an existing coding technology to achieve a relatively good codingeffect, but detailed partitioning may generate more header informationand repeated information representations, so that the coding efficiencyis reduced.

The embodiments of the application disclose a method for picturedecoding. Excessively detailed block partitioning over pictures may beavoided, the amount of header information may be reduced effectively,and repeated information representations may be avoided, so that thecoding efficiency is improved. The decoding method may be applied to acombined part of block partitioning and intra and inter predictionsignals in a hybrid video coding framework. Specifically, the decodingmethod may also be applied to a buffer part in the hybrid video codingframework. For example, FIG. 4 is a composition structure diagram of avideo coding system. As shown in FIG. 4, the video coding system 200includes a transformation and quantization unit 201, an intra estimationunit 202, an intra prediction unit 203, a motion compensation unit 204,a motion estimation unit 205, an inverse transformation and inversequantization unit 206, a filter control analysis unit 207, a filter unit208, an entropy coding unit 209, a decoded picture buffer unit 210, etc.The filter unit 208 may implement deblocking filtering and SampleAdaptive Offset (SAO) filtering. The entropy coding unit 209 mayimplement header information coding and Context-based Adaptive BinaryArithmetic Coding (CABAC).

When it is detected that an original video signal is received, for theinput original video signal, video coding blocks may be obtained bypartitioning of a CTU, and then residual pixel information obtained byintra or inter prediction is processed through the transformation andquantization unit 201 to transform the video coding blocks, includingtransforming the residual information from a pixel domain to atransformation domain and quantizing the obtained transformationcoefficient to further reduce a bit rate. The intra estimation unit 202and the intra prediction unit 203 are configured to perform intraprediction on the video coding blocks. Exactly, the intra estimationunit 202 and the intra prediction unit 203 are configured to determinean intra prediction mode to be adopted to code the video coding blocks.The motion compensation unit 204 and the motion estimation unit 205 areconfigured to execute intra prediction coding on the received videocoding blocks relative to one or more blocks in one or more referenceframes to provide time prediction information. Motion estimationexecuted by the motion estimation unit 205 is a process of generating amotion vector. The motion vector may be used for estimating a motion ofthe video coding block. Then the motion compensation unit 204 executesmotion compensation based on the motion vector determined by the motionestimation unit 205. After the intra prediction mode is determined, theintra prediction unit 203 is further configured to provide selectedintra predicted data for the entropy coding unit 209, and the motionestimation unit 205 also sends motion vector data determined bycalculation to the entropy coding unit 209. In addition, the inversetransformation and inverse quantization unit 206 is configured toreconstruct the video coding block, namely a residual block isreconstructed in the pixel domain, an artifact of a blocking effect inthe reconstructed residual block is removed through the filter controlanalysis unit 207 and the filter unit 208 and then the reconstructedresidual block is added to a predictive block in a frame of the decodedpicture buffer unit 210 to generate a reconstructed video coding block.The entropy coding unit 209 is configured to code various codingparameters and quantized transformation coefficients. In a CABAC-basedcoding algorithm, a context content may be configured to codeinformation indicating the determined intra prediction mode based onneighbouring coding blocks to output a bitstream of the video signal.The decoded picture buffer unit 210 is configured to store thereconstructed video coding block as a prediction reference. As videopictures are coded, new reconstructed video coding blocks may becontinuously generated, and all these reconstructed video coding blocksmay be stored in the decoded picture buffer unit 210.

FIG. 5 is a composition structure diagram of a video decoding system. Asshown in FIG. 5, the video decoding system 300 includes an entropydecoding unit 301, an inverse transformation and inverse quantizationunit 302, an intra prediction unit 303, a motion compensation unit 304,a filter unit 305 and a decoded picture buffer unit 306, etc. Theentropy decoding unit 301 may implement header information decoding andCABAC decoding. The filter unit 305 may implement deblocking filteringand SAO filtering. After coding processing shown in FIG. 4 is performedon an input video signal, a bitstream of the video signal is output. Thebitstream is input to the video decoding system 300, and is processedthrough the entropy decoding unit 301 at first to obtain a decodedtransformation coefficient. A residual block is generated in a pixeldomain by processing of the inverse transformation and inversequantization unit 302 for the transformation coefficient. The intraprediction unit 303 may be configured to generate predicted data of acurrent video decoding block based on a determined intra prediction modeand data of a previous decoded block from a current frame or picture.The motion compensation unit 304 determines prediction information forthe video decoding block by analyzing a motion vector and otherassociated syntactic elements and generates a predictive block of thevideo decoding block that is currently decoded by use of the predictioninformation. The residual block from the inverse transformation andinverse quantization unit 302 and the corresponding predictive blockgenerated by the intra prediction unit 303 or the motion compensationunit 304 are summed to form a decoded video block. An artifact of ablocking effect in the decoded video signal may be removed through thefilter unit 305 to improve the video quality. Then, the decoded videoblock is stored in the decoded picture buffer unit 306. The decodedpicture buffer unit 306 stores a reference picture for subsequent intraprediction or motion compensation and is also configured to output avideo signal, namely the recovered original video signal is obtained.

The method for picture decoding disclosed in the disclosure may beapplied to the encoding/decoding framework shown in FIG. 4 and FIG. 5,but no specific limits are made thereto in the embodiments of theapplication.

The technical solutions in the embodiments of the application will beclearly and completely described below in combination with the drawingsin the embodiments of the application.

In an embodiment of the application, FIG. 6 is an implementationflowchart of a method for picture decoding according to embodiments ofthe application. As shown in FIG. 6, in the embodiments of theapplication, the method for picture decoding performed by a decoder mayinclude the following operations.

In 101, bitstream data is received, and the bitstream data is parsed toobtain a CTU corresponding to the bitstream data.

In the embodiments of the application, the decoder may receive thebitstream data, and then parse the received bitstream data to obtain theCTU corresponding to the bitstream data. The decoder may obtain at leastone CTU with the same size after parsing the bitstream data.

It is to be noted that, in the embodiments of the application, anencoder encodes multiple frames of pictures in a video one by one duringvideo encoding. The frame of picture under encoding at any moment may becalled a current coded picture. The encoder, when encoding a currentcoded picture in the video, needs to partition the current coded pictureinto CTUs with the completely same size at first, and then continues tofurther partition the CTUs into CUs that are the same or different insize for encoding. For example, the encoder may partition the currentcoded picture to obtain CTUs with the completely same size of 64×64pixels, namely CTUs formed by 64×64 pixels are obtained. In theembodiments of the application, the encoder allows the CUs to overlapwhen performing overlapping partitioning on the current coded picture.For implementing parallel processing and reducing the coding complexity,the CUs do not overlap.

It is to be noted that, in the embodiments of the application, theencoder may perform overlapping partitioning and encoding on the currentcoded picture using MTT to obtain bitstream data corresponding to thecurrent coded picture, and the decoder may decode the current codedpicture according to the bitstream data to obtain the CTUs and furtherobtain the CUs.

Furthermore, in the embodiments of the application, the decoder decodesbitstream data of multiple frames of pictures in a video one by oneduring video decoding. The frame of picture under decoding at any momentmay be called a current decoding picture.

It is to be noted that, in the embodiments of the application, when thedecoder decodes the current decoding picture, CTUs do not overlap, butCUs are allowed to overlap. That is, in the embodiments of theapplication, during decoding of the decoder, multiple CUs maysimultaneously contain decoded pixel data of the same region at aposition where a reconstructed frame is buffered. One CU is relativelylarge, and may be considered as a background CU, and one CU isrelatively small, and may be considered as a refreshing CU. Data decodedand reconstructed by the background CU may be covered by pixel data ofthis position in the refreshing CU, and this is a refreshing process. Inthe application, such a decoding mode of refreshing the background CUusing the refreshing CU is a refreshing decoding.

Furthermore, in the embodiments of the application, the decoder mayselect to enable the refreshing decoding for CU refreshing during videodecoding. Specifically, the decoder may set high-layer control syntax,and it may be indicated whether the refreshing decoding is presentlysupported through enable switch syntax PPSRfrsEnbl or SPSRfrsEnbl inPicture Parameter Set (PPS) and Sequence Parameter Set (SPS).

That is, in the embodiments of the application, after the decoderreceives the bitstream data and parses the bitstream data to obtain theCTU corresponding to the bitstream data, namely after 101, a presetrefreshing mode may be enabled. Specifically, the preset refreshing modemay be configured for overlapping decoding between CUs.

In 102, an ith node of an ith layer corresponding to the CTU is parsedto obtain an ith state parameter and ith flag parameter corresponding tothe ith node, i being an integer greater than 0, the ith state parameterbeing configured to determine whether the ith node supports refreshing,and the ith flag parameter being configured to determine whether the ithnode enables refreshing.

In the embodiments of the application, the decoder may perform parsingprocessing on the ith node of the ith layer corresponding to the CTU atfirst to obtain the ith state parameter and ith flag parametercorresponding to the ith node. Specifically, i is an integer greaterthan 0. For example, i may be 1, 2, and 3.

It is to be noted that, in the embodiments of the application, the ithstate parameter may be configured to determine a default state of theith node. The ith state parameter may include an ith subtree defaultstate and an ith data default state. Specifically, the ith subtreedefault state is configured to represent a state of whether the ith nodesupports refreshing, and the ith data default state is configured todetermine whether the ith node has source data.

Furthermore, in the embodiments of the application, in a specific syntaxfor video encoding and decoding, the ith subtree default state may bedetermined through bRfrsEnblFlag, namely bRfrsEnblFlag may represent astate of whether a current node of the CTU supports refreshing.Specifically, it may be determined that the current node of the CTU doesnot support refreshing when bRfrsEnblFlag is assigned to 0, and it maybe determined that the current node of the CTU supports refreshing whenbRfrsEnblFlag is assigned to 1.

Furthermore, in the embodiments of the application, for a first node ofa first layer of the CTU, namely when i=1, a default value of the ithsubtree default state is SPSRfrsEnbl. SPSRfrsEnbl may be a flag ofwhether refreshing is supported, which may be stated in the SPS layer,or may be determined by enable control in the PPS layer. When i is not1, the ith subtree default state may be determined through a subtreedefault state of an upper layer, namely the ith subtree default statemay be determined according to an (i−1)th subtree default state.

Furthermore, in the embodiments of the application, in the specificsyntax for video encoding and decoding, the ith data default state maybe determined through bAncFlag, namely bAncFlag may represent whetherthe current node of the CTU has source data. Specifically, it may bedetermined that the current node of the CTU has no source data whenbAncFlag is assigned to 0, and it may be determined that the currentnode of the CTU has the source data when bAncFlag is assigned to 1.

Furthermore, in the embodiments of the application, for the first nodeof the first layer of the CTU, namely when i=1, a default value of theith data default state is 0. When i is not 1, the ith data default statemay be determined through a data default state of the upper layer,namely the ith data default state may be determined according to an(i−1)th data default state.

It is to be noted that, in the embodiments of the application, the ithflag parameter may be configured to determine a data flag of the ithnode. The ith state parameter may include an ith subtree identifier andan ith data identifier. Specifically, the ith subtree identifier isconfigured to represent whether there is a CU that may be refreshed on asubtree of the ith node, and the ith data identifier is configured todetermine whether the ith node has data.

Furthermore, in the embodiments of the application, in the specificsyntax for video encoding and decoding, the ith subtree identifier maybe determined through Refresh_CU_enable_flag[x0][y0], namelyRefresh_CU_enable_flag[x0][y0] may represent whether the current node ofthe CTU has a CU that may be refreshed. Specifically, it may bedetermined that the current node of the CTU has no CU that may berefreshed when Refresh_CU_enable_flag[x0][y0] is assigned to 0, and itmay be determined that the current node of the CTU has the CU that maybe refreshed when Refresh_CU_enable_flag[x0][y0] is assigned to 1.

Furthermore, in the embodiments of the application, in the specificsyntax for video encoding and decoding, the ith data identifier may bedetermined through Refresh_CU_flag[x0][y0], namelyRefresh_CU_flag[x0][y0] may represent whether the current node of theCTU has data. Specifically, it may be determined that the current nodeof the CTU has no data when Refresh_CU_flag[x0][y0] is assigned to 0,and it may be determined that the current node of the CTU has the datawhen Refresh_CU_flag[x0][y0] is assigned to 1.

Furthermore, in the embodiments of the application, in specific syntaxtransmission for video encoding and decoding, bAncFlag,Refresh_CU_enable_flag[x0][y0], and Refresh_CU_flag[x0][y0] may not betransmitted. Specifically, whether Refresh_CU_flag[x0] [y0] andRefresh_CU_flag[x0][y0] exist depend on whether the current node is aleaf node and values of bRfrsEnblFlag and bAncFlag.

It is to be noted that, in the embodiments of the application, the CTUmay correspond to at least one layer of nodes, and any node of eachlayer may have data. Data of an ancestor node may be covered by data ofa descendant node thereof. Therefore, the decoder, when decoding theCTU, needs to detect whether the nodes have data layer by layer, and mayfurther perform decoding processing on nodes with data to constructcorresponding CUs. By contrast, in the conventional art, for a CTU, dataonly exists on nodes that may not be continued to be partitioned, i.e.,leaves, in a tree structure, so that the decoder needs to performparsing and decoding processing on each leaf. FIG. 7 is a structurediagram of a CTU according to the conventional art. FIG. 8 is astructure diagram of a CTU according to embodiments of the application.As shown in FIGS. 7 and 8, for a same CTU, since overlappingpartitioning of CUs is not allowed in the conventional art, only leavesin a tree structure corresponding to the CTU may have data, and thedecoder needs to perform data parsing on all the leaves to construct CUsduring decoding. In the embodiments of the application, overlappingpartitioning of CUs is allowed, so that data may exist on anyintermediate node in the tree structure corresponding to the CTU. Forany CTU, it is unnecessary to perform data parsing on all the leaves;and instead, it may be detected whether there is data on each node, andif there is data, decoding is performed to obtain a corresponding CU. Insuch a manner, partitioning of a large number of small blocks isavoided, and the decoding efficiency may be improved. Furthermore, inthe embodiments of the application, the encoder, during pictureencoding, not only takes a leaf node as an encoding unit, but also mayperform compressive encoding on intermediate nodes. However, nodeinformation of part of descendant nodes needs to be removed from theintermediate nodes, which may be implemented by, for example, masksperformed in a manner of zero padding, interpolation, or extensionsupplementation. Comparison between FIG. 7 and FIG. 8 shows that theencoder encodes multiple irregular regions in one region in acentralized manner, so that the detailing degree of coding partitioningmay be reduced. A region originally different from a background istemporarily considered to be the same as other background regions bydata extension to reduce the number of bits for representation, and ablock different from the background further needs to be encodedindependently to refresh and cover the background block to obtain apicture content the same as the original one. In such case, it is notneeded to perform certain partitioning in the original partitioningtree, so that part of header information is reduced. Moreover, a flatpicture region mainly includes low-frequency component, and allcorresponding energy is concentrated in the upper-left corner of theregion, reduction of partitioning is more favorable for energyconcentration, and compared with over-partitioning, may also reduce partof frequency-domain data after pixel-domain transformation.Specifically, the dotted part in the partitioning tree in FIG. 8 has novalid data, so that partition information of this part may be omitted.

Furthermore, in the embodiments of the application, ith-layer datacorresponding to the CTU may include at least one node, so that the ithnode of the ith layer corresponding to the CTU means all nodes in theith layer. That is, the decoder may perform detection processing on allthe ith nodes of the ith layer corresponding to the CTU to obtain adetection result corresponding to each ith node, namely all detectionresults corresponding to all the nodes of the ith layer are obtained bydetection.

In 103, detection processing is performed on the ith node according tothe ith state parameter and the ith flag parameter to obtain an ithdetection result.

In the embodiments of the application, the decoder, after performingparsing processing on the ith node of the ith layer corresponding to theCTU to obtain the ith state parameter and ith flag parametercorresponding to the ith node, may perform detection processing on theith node according to the ith state parameter and the ith flag parameterto obtain the ith detection result.

It is to be noted that, in the embodiments of the application, thedecoder, after determining the ith state parameter and the ith flagparameter, may further determine whether the ith node has data or not incombination with a leaf parameter of the ith node and according to theith state parameter and the ith flag parameter.

Furthermore, in the embodiments of the application, the leaf parameterof the ith node may be configured to determine whether the ith node is aleaf in the CTUt.

It is to be noted that, in the embodiments of the application, thedecoder, when performing detection processing on the ith node accordingto the ith state parameter and the ith flag parameter to obtain the ithdetection result, may determine the leaf parameter corresponding to theith node at first, the leaf parameter being configured to determinewhether to continue to partition the ith node or not, and then obtainthe ith detection result according to the leaf parameter, the ith stateparameter and the ith flag parameter. That is, the decoder may determinewhether the ith node may be continued to be partitioned according to theleaf parameter corresponding to the ith node.

Furthermore, in the embodiments of the application, for determiningwhether the ith node has data and may be continued to be partitioned,the decoder performs detection processing on the ith node, andcorrespondingly, the ith detection result may include four results,i.e., the node has data and is to be partitioned, the node has no dataand is to be partitioned, the node has data and is not to bepartitioned, and the node has no data and is not to be partitioned.

It is to be noted that, in the embodiments of the application, inspecific syntax transmission for video encoding and decoding, sincebAncFlag, Refresh_CU_enable_flag[x0][y0], and Refresh_CU_flag[x0][y0]may not be transmitted, the decoder needs to further infer and determinewhether the ith node has data according to the leaf parameter, the ithstate parameter, and the ith flag parameter.

In 104, an (i+1)th node of an (i+1)th layer corresponding to the CTU isacquired according to the ith detection result.

In the embodiments of the application, the decoder, after performingdetection processing on the ith node according to the ith stateparameter and the ith flag parameter to obtain the ith detection result,may acquire the (i+1)th node of the (i+1)th layer corresponding to theCTU according to the ith detection result.

It is to be noted that, in the embodiments of the application, after thedecoder performs detection processing to obtain the ith detectionresult, since the ith detection result may include four results, i.e.,the node has data and is to be partitioned, the node has no data and isto be partitioned, the node has data and is not to be partitioned, andthe node has no data and is not to be partitioned may be obtained, thedecoder may further correspondingly process the ith node according todifferent detection results.

Furthermore, in the embodiments of the application, when the ithdetection result is that the node has data and is to be partitioning,the decoder may acquire ith CU data of the ith layer, and then performpartitioning processing on the ith node to obtain the (i+1)th node ofthe (i+1)th layer corresponding to the CTU.

It is to be noted that, in the embodiments of the application, if thedecoder determines that the ith node has data and partitioningprocessing may be continued to be performed on the ith node afterperforming detection processing on the ith node, the decoder needs toacquire corresponding data at first, namely obtaining the data of theith CU corresponding to the ith node in the CTU. Since the ith layercorresponding to the CTU may include at least one ith node, the decoder,after sequentially performing detection processing on all the ith nodesof the ith layer, may perform data acquisition on the ith node of whichthe detection result is that there is data to obtain the data of the ithCU corresponding to the ith node. Furthermore, the decoder, afterobtaining the corresponding data of the ith CU, may continue to performpartitioning processing on the ith node to obtain a node of a lowerlayer of the ith layer, namely obtaining the (i+1)th node of the (i+1)thlayer corresponding to the CTU.

Furthermore, in the embodiments of the application, when the ithdetection result is the node has no data and is to be partitioned,partitioning processing is performed on the ith node to obtain the(i+1)th node of the (i+1)th layer corresponding to the CTU. In theembodiments of the application, after the decoder performs detectionprocessing on the ith node of the ith layer corresponding to the CTU toobtain the ith detection result, if the ith detection result is that thenode has no data and is to be partitioned, the decoder does not need toperform data acquisition, but directly performs partitioning processingto obtain the node of the lower layer, i.e., the (i+1)th node of the(i+1)th layer.

Furthermore, in the embodiments of the application, since the ith layercorresponding to the CTU may include at least one ith node, the decoder,after sequentially performing detection processing on all the ith nodesof the ith layer, may perform partitioning processing on the ith node ofwhich the detection result is that partitioning may be continued toobtain the (i+1)th node of the (i+1)th layer corresponding to each ithnode. That is, for each ith node that may be continued to bepartitioned, the decoder may obtain at least one (i+1)th node bypartitioning.

It can thus be seen that, in the embodiments of the application, if theith node may be partitioned, no matter whether the ith node has data,the decoder needs to continue to perform partitioning processing on theith node, thereby obtaining the (i+1)th node of the (i+1)th layer.

Furthermore, in the embodiments of the application, when the ithdetection result is that the node has data and is not to be partitioned,the data of the ith CU of the ith layer is acquired, and parsingprocessing of the ith node is ended.

It is to be noted that, in the embodiments of the application, if thedecoder determines that the ith node has data and partitioningprocessing may not be continued to be performed on the ith node afterperforming detection processing on the ith node, the decoder needs toacquire corresponding data at first, namely obtaining the data of theith CU corresponding to the ith node in the CTU. Since the ith layercorresponding to the CTU may include at least one ith node, the decoder,after sequentially performing detection processing on all the ith nodesof the ith layer, may perform data acquisition on the ith node of whichthe detection result is that there is data to obtain the data of the ithCU corresponding to the ith node. Furthermore, since the ith node maynot be continued to be partitioned, the decoder may end parsingprocessing of the ith node after obtaining the corresponding data of theith CU.

Furthermore, in the embodiments of the application, when the ithdetection result is the node has no data and is not to be partitioned,the decoder does not need to perform data acquisition, meanwhile, alsodoes not need to perform partitioning processing, but directly endsparsing processing of the ith node.

It is to be noted that, in the embodiments of the application, theencoder may determine whether there is data in each rectangular regiongenerated by partitioning, and if there is data, acquire CU datacorresponding to this node. For example, for the ith node that has data,the data of the ith CU corresponding to the ith node may be acquired.Furthermore, in the embodiments of the application, the data of the ithCU may include identification information, prediction information, atransformation coefficient, etc. Furthermore, the decoder may obtaincorresponding ith background pixel data according to the data of the ithCU.

In 105, detection processing is continued to be performed on the (i+1)thnode, and all nodes corresponding to the CTU are traversed until data ofall CUs corresponding to the CTU is obtained.

In the embodiments of the application, the decoder, after acquiring the(i+1)th node of the (i+1)th layer corresponding to the CTU according tothe ith detection result, may continue to perform detection processingon the (i+1)th node, and then traverse all the nodes corresponding tothe CTU, namely detection processing is performed on all the nodes ofthe CTU until all the CUs corresponding to the CTU are obtained.

It is to be noted that, in the embodiments of the application, thedecoder, after obtaining the (i+1)th node of the (i+1)th layer bypartitioning, may continue to perform detection processing on the(i+1)th node according to the method from 101 to 104 to obtain data ofthe (i+1)th CU corresponding to the (i+1)th node and an (i+2)th node ofan (i+2)th layer, and may obtain data of all the CUs corresponding tothe CTU after recursive processing according to the method from 101 to104.

Furthermore, in the embodiments of the application, for a node of anylayer of the CTU, the decoder may perform recursive processing accordingto the method from 101 to 104. That is, for any one node, the decodermay perform detection processing according to a state parameter and aflag parameter. For a node that has data and is to be partitioned, dataacquisition is performed to obtain data of corresponding CU, andpartitioning processing is continued to be performed to obtain a node ofthe lower layer. For a node that has no data and is to be partitioned,partitioning processing is directly performed to obtain a node of thelower layer. For a node that has data and is not to be partitioned, dataacquisition is performed to obtain data of corresponding CU, anddecoding processing is ended. For a node that has no data and is not tobe partitioned, decoding processing is directly ended. In summary, thedecoder may perform recursive processing on the CTU layer by layeraccording to the method from 101 to 104 to obtain data of all CUscorresponding to the CTU.

In 106, a decoded picture corresponding to the bitstream data isgenerated according to all the nodes and data of all CUs.

In the embodiments of the application, the decoder, after obtaining dataof all CUs corresponding to the CTU, may generate the decoded picturecorresponding to the bitstream data according to all the nodes and dataof all CUs.

It is to be noted that, in the embodiments of the application, thedecoder, when generating the decoded picture corresponding to thebitstream data according to all the nodes and the data of all CUs, mayperform decoding processing on the data of all CUs at first to obtaindata of all pixels corresponding to the CTU, and then may generate thedecoded picture corresponding to the bitstream data according to thedata of all pixels.

Furthermore, in the embodiments of the application, when the decoderperforms decoding processing on the data of CUs to obtain the data ofall pixels corresponding to the CTU, if the ith node has data and is notto be partitioned segmented, the decoder may decode the data of the ithCU to obtain ith pixel data. If the ith node has data and is to bepartitioned, the ith CU data is decoded to obtain the ith backgroundpixel data, and (i+1)th CU data is decoded to obtain ith refreshingpixel data to obtain the ith pixel data. All the nodes are traverseduntil the data of all pixels is obtained.

Furthermore, in the embodiments of the application, when the decodergenerates the decoded picture corresponding to the bitstream dataaccording to the data of all pixels, if the ith node has data and is tobe partitioned, refreshing processing is performed on the ith backgroundpixel data according to the ith refreshing pixel data to obtainrefreshed pixel data, namely the ith pixel data is obtained. All thenodes are continued to be traversed until the decoded picture isobtained.

That is, if the ith node may not to be continued to be partitioned,namely the ith node is a leaf node in the CTU, the ith pixel dataobtained by the decoder by decoding is pixel data corresponding to anith CU. If the ith node may be continued to be partitioned, namely theith node is not a leaf node in the CTU, the decoder needs to acquirepixel data corresponding to an (i+1)th CU of the (i+1)th node and thenrefresh a corresponding region of the pixel data corresponding to theith CU according to the pixel data corresponding to the (i+1)th CU ofthe (i+1)th node to obtain the pixel data corresponding to the ith CU.

It is to be noted that, in the embodiments of the application, thedecoder, when performing decoding processing on data of all CUs toobtain the data of all pixels corresponding to the CTU, may decodelower-layer data at first and then decode upper-layer data.Specifically, when the decoder performs decoding processing on the dataof all CUs to obtain the data of all pixels corresponding to the CTU, ifthe ith node has data and is to be partitioned, the decoder may acquireand decode the data of the (i+1)th CU to obtain the ith refreshing pixeldata corresponding to the ith node, then decode the data of the ith CUto obtain the ith pixel data, and set the ith background pixel data as abackground of the ith refreshing pixel data, thereby obtaining the ithCU. The decoder may continue to traverse all the nodes until the data ofall pixels is obtained.

It is to be noted that, in the embodiments of the application, if theith detection result is that there is no data, the ith background pixeldata is kept null.

It is to be noted that, in the embodiments of the application, thedecoder, when generating the decoded picture according to the data ofall CUs, may perform decoding processing on the data of all CUs at firstto obtain the data of all pixels corresponding to the CTU. If backgroundpixel data corresponding to a background CU in the data of all pixelsand refreshing pixel data corresponding to a refreshing CU have anoverlapping region, the decoder may replace the pixel data of thecorresponding region of the background CU according to the pixel data ofthe refreshing CU, namely the background CU is refreshed with therefreshing CU.

That is, in the embodiments of the application, when the decodergenerates the decoded picture corresponding to the bitstream dataaccording to all the CUs, if pixel data corresponding to an mth CU inall the CUs and pixel data corresponding to an nth CU have anoverlapping region, the decoder may perform refreshing processing on thepixel data corresponding to the mth CU according to the pixel datacorresponding to the nth CU to generate the decoded picture. Here, m isan integer greater than 0, and n is an integer greater than m. That is,the nth CU is a refreshing CU of the mth CU.

In the conventional art, when the encoder encodes a video picture, CUsdo not overlap, so that any detailed picture information needs detailedpartition of CUs, and correspondingly, when the decoder decodes thevideo picture, CUs obtained by decoding may also have no overlappingregions. By contrast, according to the method for picture decodingdisclosed in the embodiments of the application, since overlapping ofCUs is supported during picture encoding of the encoder, detailedpartition of the picture may be avoided, and correspondingly, when thedecoder decodes the video picture, if the background pixel datacorresponding to the background CU in the data of all pixels and therefreshing pixel data corresponding to the refreshing CU have anoverlapping region, the decoder may replace the pixel data of thecorresponding region of the background CU according to the pixel data ofthe refreshing CU, namely the background CU is refreshed with therefreshing CU.

Furthermore, in the embodiments of the application, in a decodingprocess, the data, such as prediction information, identificationinformation, and a transformation coefficient, etc., of the backgroundCU may also be refreshed with the data of the refreshing CU.

That is, in the embodiments of the application, in the decoding processof the decoder, the buffered pixel data, or the prediction information,the identification information, the transformation coefficient, etc.,use present latest data. The latest data may be the pixel datacorresponding to the background CU of the CTU, and may be either data ofthe background CU that has not been refreshed or data after replacementwith the decoded picture of the refreshing CU.

It is to be noted that, in the embodiments of the application, theencoder and the decoder may also allow regional overlapping of CUs inprediction and/or transformation links. Correspondingly, a CTU mayinclude a corresponding background PU and refreshing PU, and may alsoinclude a corresponding background TU and refreshing TU.

Furthermore, in the embodiments of the application, in the decodingprocess, the decoder may refresh information for subsequent blockprediction timely or untimely.

Based on the method for picture decoding disclosed in 101 to 106, FIG. 9is a first flowchart of a method for picture decoding according toembodiments of the application. As shown in FIG. 9, for any node thatmay be continued to be partitioned in the CTU, the decoder may performparsing processing at first, and determine whether the node has dataaccording to a state parameter and flag parameter obtained by parsingprocessing. If a detection result is that there is data, the decoder mayacquire the data to obtain corresponding identification information,prediction information and transformation coefficient to obtain acorresponding CU by decoding processing, and then enter a partitioningprocessing flow. If the detection result is that there is no data, thedecoder may directly enter the partitioning processing flow. In thepartitioning processing flow, the decoder may determine whether QTpartitioning may be performed on the node. If it is determined that QTmay not be performed, the decoder may continue to determine whether BTpartitioning or TT partitioning may be performed on the node. If QTpartitioning may be performed, it may be determined whether QTpartitioning may be performed on each node obtained by partitioningafter QT partitioning is performed on the node, if YES, each node isrecursively decoded, and if NO, whether BT partitioning or TTpartitioning may be performed on each node obtained by partitioning maybe continued to be determined. When BT partitioning or TT partitioningis being determined, it is necessary to determine a partitioningdirection of BT partitioning or TT partitioning, namely determiningwhether vertical partitioning or horizontal partitioning is to beperformed, and finally, each node obtained by partitioning isrecursively decoded. Finally, data of all CUs corresponding to the CTUmay be obtained.

It is to be noted that, in the embodiments of the application, for thecondition that there is data on an upper-left side corresponding to theCTU, the decoder may recursively decode an upper-left CU at first, andthen parse the data. For the condition that there is data on a left sidecorresponding to the CTU, the decoder may recursively decode a left CUat first, and then parse the data. For the condition that there is dataon an upper side corresponding to the CTU, the decoder may recursivelydecode an upper CU, and then parse the data.

Furthermore, in the embodiments of the application, the decoder, whendecoding the picture, may further perform the flow of determiningwhether a node has data on each branch after partitioning identifierparsing of the node, so that the number of bits for signal transmissionmay be reduced effectively. Based on FIG. 9, FIG. 10 is a secondflowchart of a method for picture decoding according to embodiments ofthe application. As shown in FIG. 10, for any node that may be continuedto be partitioned in any CTU, the decoder may determine whether QTpartitioning may be performed on the node. If it is determined that QTpartitioning may not be performed, the decoder may continue to determinewhether BT partitioning or TT partitioning may be performed on the node.If QT partitioning may be performed, whether QT partitioning may beperformed on each node obtained by partitioning may be determined afterQT partitioning is performed on the node, if YES, each node isrecursively decoded to obtain a partitioning identifier on a branch onthe node, and if NO, whether BT partitioning or TT partitioning may beperformed on each node obtained by partitioning may be continued to bedetermined to obtain the partitioning identifier on the branch on thenode. After the partitioning identifier on each branch of the node isobtained by parsing, the decoder may perform parsing processing on eachbranch, and then determine whether the node has data according to astate parameter and flag parameter obtained by parsing processing. Ifthere is data, the decoder may acquire the data to obtain correspondingidentification information, prediction information and transformationcoefficient to obtain a CU corresponding to the node, and recursivelydecode each branch after partitioning. If there is no data, the decodermay directly recursively decode each branch after partitioning. Finally,data of all CUs corresponding to the CTU may be obtained.

The embodiments of the application provide a method for picturedecoding. The decoder receives the bitstream data, and parses thebitstream data to obtain the CTU corresponding to the bitstream data.The ith node of the ith layer corresponding to the CTU is parsed toobtain the ith state parameter and ith flag parameter corresponding tothe ith node, i being an integer greater than 0, the ith state parameterbeing configured to determine whether the ith node supports refreshing,and the ith flag parameter being configured to determine whether the ithnode enables refreshing. Detection processing is performed on the ithnode according to the ith state parameter and the ith flag parameter toobtain the ith detection result. The (i+1)th node of the (i+1)th layercorresponding to the CTU is acquired according to the ith detectionresult. Detection processing is continued to be performed on the (i+1)thnode, and the all nodes corresponding to the CTU are traversed untildata of the all CUs corresponding to the CTU is obtained. The decodedpicture corresponding to the bitstream data is generated according tothe all nodes and data of the all CUs. It can be seen that, in theembodiments of the application, in a process of decoding an picture in avideo, after bitstream data is received and parsed to obtain a CTU,parsing processing may be performed on a node of each layercorresponding to the CTU to obtain a state parameter and flag parametercorresponding to the node of this layer, then detection processing isperformed on the node according to the state parameter and the flagparameter, and decoding processing is performed on nodes that have data,to obtain all CUs corresponding to the CTU to obtain a correspondingdecoded picture. Since overlapping partitioning of CUs is supportedduring coding, if all the CUs obtained by the decoder by the decodingnodes that have data include at least two regionally overlapping CUs,the decoder may perform refreshing processing on picture informationcorresponding to a background CU according to picture informationcorresponding to a refreshing CU. Therefore, over-partitioning of videopictures may be avoided, unnecessary header information may be reduced,distributed repeated representations of data with similar features inthe same region may be avoided, and the coding efficiency may further beimproved.

In another embodiment of the application, based on the abovementionedembodiment, for 102, a method that the decoder determines whether theith node has data according to the ith state parameter and the ith flagparameter may include the following operations.

In 103 a, a leaf parameter corresponding to the ith node is determined,the leaf parameter being configured to determine whether to continue topartition the ith node.

In the embodiments of the application, the decoder may determine theleaf parameter of the ith node at first. Specifically, the leafparameter may be configured to determine whether the ith node iscontinued to be partitioned. That is, the decoder determines whether theith node is a leaf of the CTU at first.

It is to be noted that, in the embodiments of the application, if theith node is a leaf, namely the ith node has no branch, the decoder maydetermine that the ith node is not required to be refreshed, butdirectly performs a normal decoding flow.

It is to be noted that, in the embodiments of the application, if theith node is not a leaf, namely the ith node has a branch, the decodermay further determine whether to refresh the ith node.

Furthermore, in the embodiments of the application, it may indicate thatthe ith node is not a leaf node when the leaf parameter is assigned to0, and it may indicate that the ith node is a leaf node when the leafparameter is assigned to 1.

In 103 b, the ith detection result is obtained according to the leafparameter, the ith state parameter, and the ith flag parameter.

In the embodiments of the application, the decoder, after determiningthe leaf parameter of the ith node, may obtain the ith detection resultaccording to the leaf parameter, the ith state parameter, and the ithflag parameter.

It is to be noted that, in the embodiments of the application, inspecific syntax transmission for video encoding and decoding, sincebAncFlag, Refresh_CU_enable_flag[x0][y0], and Refresh_CU_flag[x0][y0]may not be transmitted, and in addition, Refresh_CU_flag[x0][y0] andRefresh_CU_flag[x0][y0] exist depend on whether the present node is aleaf node or not and bRfrsEnblFlag and bAncFlag, the decoder needs tofurther infer and determine whether the ith node has data according tothe leaf parameter, the ith state parameter, and the ith flag parameter.

In the embodiments of the application, furthermore, the decoder, beforecontinuing to perform parsing processing, partitioning processing,and/or decoding processing on the (i+1)th node, needs to transmit an(i+1)th state parameter at first according to the leaf parameter, theith state parameter, and the ith flag parameter.

It is to be noted that, in the embodiments of the application, the(i+1)th state parameter may be configured to determine a default stateof the (i+1)th node. The (i+1)th state parameter may include an (i+1)thsubtree default state and an (i+1)th data default state. Specifically,the (i+1)th subtree default state is configured to represent a state ofwhether the (i+1)th node supports refreshing, and the (i+1)th datadefault state is configured to determine whether the (i+1)th node hassource data.

Furthermore, in the embodiments of the application, for the (i+1)th nodeof the CTU, the (i+1)th subtree default state may be determined througha subtree default state of an upper layer, namely the (i+1)th subtreedefault state may be determined according to the ith subtree defaultstate.

Furthermore, in the embodiments of the application, for the (i+1)th nodeof the CTU, the (i+1)th data default state may be determined through adata default state of the upper layer, namely the (i+1)th data defaultstate may be determined according to the ith data default state.

Furthermore, in the embodiments of the application, the decoder, whentransmitting the (i+1)th state parameter according to the leafparameter, the ith state parameter, and the ith flag parameter, maydetermine whether to perform state refreshing at first according to theleaf parameter, the ith state parameter, and the ith flag parameter. Ifit is determined to perform default state refreshing, the decoder mayperform refreshing processing on the ith state parameter to obtain the(i+1)th state parameter. If it is determined not to perform staterefreshing, the decoder may determine the ith state parameter as the(i+1)th state parameter.

Table 1 is a combined analysis table of syntax transmission and staterefreshing conditions in the embodiments of the application. As shown inTable 1, the decoder may further determine whether a node has data,namely determining whether to decode the node, according to fiveparameters, i.e., a leaf parameter of the node, a subtree default staterepresented by bRfrsEnblFlag, a data default state represented bybAncFlag, a subtree flag represented by Refresh_CU_enable_flag[x0][y0],and a data flag represented by Refresh_CU_flag[x0][y0]. In addition, thedecoder may further determine a subtree default state and data defaultstate of a node of a lower layer through the five parameters of thenode. For the first node of the first layer of the CTU, namely when i=1,the default value of the first subtree default state is SPSRfrsEnbl,SPSRfrsEnbl being a flag of whether refreshing is supported, which maybe stated in the SPS layer, or may be determined by enable control inthe PPS layer. A default value of the first data default state is 0.

TABLE 1 Combined Analysis Table of Syntax Transmission and StateRefreshing Conditions Subtree Data default default state of state ofLeaf Subtree Data the the Whether para- default default Subtree Datalower lower to meter state state flag flag layer layer decode 0 0   —  No refresh No refresh 0 0 1 0 0   0 No refresh 0 0 1 0 1 1 1 1 1 0 1 0 10 1 0 0 0 1 1   1 1 1 1 0 1 1   0 1 1 0 1 0       No refresh No refresh1 1 1 0     No refresh No refresh 1 1 1 1   1 No refresh No refresh 1 11 1   0 No refresh No refresh 0 0 1 0 0   0 No refresh 0

Furthermore, based on Table 1, when a node in the CTU is not a leafnode, namely a leaf parameter is 0, a subtree default statebRfrsEnblFlag is assigned to 1, namely CU refreshing processing of asubtree is supported, a data default state bAncFlag is 0, namely thenode has no source data, a subtree flag Refresh_CU_enable_flag[x0][y0]is 0, namely there is no CU that may be refreshed on the subtree of thenode, and a data flag Refresh_CU_flag[x0] [y0] is not transmitted, thedecoder may determine that the node has data according to the above fiveparameters, and thus determine not to perform decoding processing on thenode. Furthermore, the decoder may refresh a subtree default state of alower layer according to the subtree default state bRfrsEnblFlag of thenode, namely the subtree default state transmitted to the lower layer isassigned to 1. In addition, the decoder may determine not to refresh adata default state of the lower layer, namely the data default statetransmitted to the lower layer is still 0.

Based on Table 1, FIG. 11 is a schematic diagram of a state parameterand a flag parameter according to embodiments of the application. Asshown in FIG. 11, for the first node of the first layer of the CTU, thesubtree default state bRfrsEnblFlag of the first node is assigned to 1,namely CU refreshing processing of the subtree is supported, differentsubtrees of the first node having different supporting conditions, thedata default state bAncFlag is 0, namely the node has no source data,the subtree flag Refresh_CU_enable_flag[x0][y0] is 1, namely there is aCU that may be refreshed on the subtree of the first node, and the dataflag Refresh_CU_flag[x0][y0] is 0, namely the first node has no data.Since the first node is not a leaf node, namely the leaf parameter is 0,the decoder may determine not to perform decoding processing on thefirst node based on Table 1, and meanwhile, may determine that thesubtree default state transmitted to the node of the lower layer is 1and the data default state is 0. It can be seen that, for four secondnodes of a second layer of the CTU, all subtree default states are 1,and all data default states are 0.

The embodiments of the application provide the method for picturedecoding, the decoder, and the storage medium. The decoder receives thebitstream data, and parses the bitstream data to obtain the CTUcorresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and all the nodescorresponding to the CTU are traversed until data of all CUscorresponding to the CTU is obtained. The decoded picture correspondingto the bitstream data is generated according to the all nodes and thedata of all CUs. It can be seen that, in the embodiments of theapplication, in a process of decoding a picture in a video, afterbitstream data is received and parsed to obtain a CTU, parsingprocessing may be performed on a node of each layer corresponding to theCTU to obtain a state parameter and flag parameter corresponding to thenode of this layer, then detection processing is performed on the nodeaccording to the state parameter and the flag parameter, and decodingprocessing is performed on nodes that have data, to obtain all CUscorresponding to the CTU to obtain a corresponding decoded picture.Since overlapping partitioning of CUs is supported during coding, if allthe CUs obtained by the decoder by decoding nodes that have data includeat least two regionally overlapping CUs, the decoder may performrefreshing processing on picture information corresponding to abackground CU according to picture information corresponding to arefreshing CU. Therefore, over-partitioning of video pictures may beavoided, unnecessary header information may be reduced, distributedrepeated representations of data with similar features in the sameregion may be avoided, and the coding efficiency may further beimproved.

Based on the abovementioned embodiments, a method that the decoderperforms partitioning processing on the ith node to obtain the (i+1)thnode of the (i+1)th layer corresponding to the CTU may include thefollowing operations.

In 201, an ith partitioning mode corresponding to the ith node isacquired.

In the embodiments of the application, the decoder, when partitioningthe ith node, may acquire the ith partitioning mode corresponding to theith node at first.

It is to be noted that, in the embodiments of the application, the ithpartitioning mode may include one of the following partitioning modes:QT, QTBT, TT, BT, etc. It is to be noted that the ith partitioning modemay also be MTT. MTT is not a solution parallel to QT, BT, and TT, andincludes multiple partitioning methods, namely it is a generic term incase of coexistence of QT, BT, and TT. QTBT, similar as MTT, is not asolution parallel to QT and BT, and includes multiple partitioningmethods, namely it is a generic term in case of coexistence of QT andBT.

In 202, partitioning processing is performed on the ith node accordingto the ith partitioning mode to obtain the (i+1)th node.

In the embodiments of the application, the decoder, after acquiring theith partitioning mode corresponding to the ith node, may performpartitioning processing on the ith node according to the ithpartitioning mode to obtain the (i+1)th node.

It is to be noted that, in the embodiments of the application, thedecoder performs partitioning processing on the ith node based on theith partitioning mode, and each ith node may be partitioned to obtain atleast two leaves, namely at least two (i+1)th nodes may be obtained.

The embodiments of the application provide the method for picturedecoding, the decoder, and the storage medium. The decoder receives thebitstream data, and parses the bitstream data to obtain the CTUcorresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and all nodescorresponding to the CTU are traversed until data of all CUscorresponding to the CTU is obtained. The decoded picture correspondingto the bitstream data is generated according to all nodes and the dataof all CUs. It can be seen that, in the embodiments of the application,in a process of decoding a picture in a video, after bitstream data isreceived and parsed to obtain a CTU, parsing processing may be performedon a node of each layer corresponding to the CTU to obtain a stateparameter and flag parameter corresponding to the node of this layer,then detection processing is performed on the node according to thestate parameter and the flag parameter, and decoding processing isperformed on nodes that have data, to obtain all CUs corresponding tothe CTU to obtain a corresponding decoded picture. Since overlappingpartitioning of CUs is supported during coding, if all the CUs obtainedby the decoder by decoding nodes that have data include at least tworegionally overlapping CUs, the decoder may perform refreshingprocessing on picture information corresponding to a background CUaccording to picture information corresponding to a refreshing CU.Therefore, over-partitioning of video pictures may be avoided,unnecessary header information may be reduced, distributed repeatedrepresentations of data with similar features in the same region may beavoided, and the coding efficiency may further be improved.

In another embodiment of the application, based on the abovementionedembodiments, partitioning processing during picture decoding of thedecoder is exemplarily described according to the method for picturedecoding from 101 to 106.

FIG. 12 is a first schematic diagram of partitioning processing. FIG. 13is a second schematic diagram of partitioning processing. As shown inFIG. 12 and FIG. 13, all of the upper-left coding block A21, upper-rightcoding block A22, bottom-left coding block A23 and bottom-right codingblock A24 obtained after QT partitioning is performed on a first nodeA11 that has no data in a CTU have data, namely all of four second nodesof a second layer of the CTU have data. Since A23 may be furtherpartitioned, the encoder may perform QT partitioning on A23 to obtainfour third nodes of a third layer, all the four third nodes having nodata. Vertical BT partitioning may further be performed on one thirdnode, and two fourth nodes A41 and A42 of a fourth layer are obtained bypartitioning. Both A41 and A42 may not be further partitioned, and A42has data. It can thus be seen that, according to the method for picturedecoding provided in the disclosure, it is only necessary to performdecoding processing on A21, A22, A23, A24 and A42 that have data toobtain corresponding CUs. Since A42 and A23 have an overlapping region,the decoder may refresh the CU corresponding to A23 according to the CUcorresponding to A42 to finally obtain a decoded picture correspondingto the CTU.

FIG. 14 is a third schematic diagram of partitioning processing. FIG. 15is a fourth schematic diagram of partitioning processing. As shown inFIG. 14 and FIG. 15, a first node of a first layer of a CTU has data. Inthe upper-left coding block B21, upper-right coding block B22,bottom-left coding block B23 and bottom-right coding block B24 obtainedafter QT partition is performed on a first node B11, B23 has data. SinceB23 may be further partitioned, the encoder may perform QT partitioningon B23 to obtain four third nodes of a third layer, all the four thirdnodes having no data. Vertical BT partitioning may further be performedon one third node, and two fourth nodes B41 and B42 of a fourth layerare obtained by the partitioning. Both B41 and B42 may not be furtherpartitioned, and B42 has data. It can thus be seen that, according tothe method for picture decoding provided in the disclosure, it is onlynecessary to perform decoding processing on B11, B23 and B42 that havedata to obtain corresponding CUs. Since B23 and B11 have an overlappingregion, and B23 and B42 have an overlapping region, the decoder mayrefresh the CU corresponding to B11 according to the CU corresponding toB23 to obtain a refreshed CU corresponding to B23, and then refresh therefreshed CU corresponding to B23 according to the CU corresponding toB42 to finally obtain a decoded picture corresponding to the CTU.

FIG. 16 is a fifth schematic diagram of partitioning processing. FIG. 17is a sixth schematic diagram of partitioning processing. As shown inFIG. 16 and FIG. 17, a first node of a first layer of a CTU has data,and all of the upper-left coding block C21, upper-right coding blockC22, bottom-left coding block C23 and bottom-right coding block C24obtained after QT partitioning is performed on a first node C11 have nodata. Since C22 and C23 may be further partitioned, the coder mayperform QT partitioning on C22 and C23 respectively to obtain eightthird nodes of a third layer, including four third nodes correspondingto C22 and four third nodes corresponding to C23, all the eight thirdnodes having no data. Vertical BT partitioning may further be performedon two third nodes, and four fourth nodes C41, C42, C43 and C44 of afourth layer are obtained by the partitioning. All of C41, C42, C43, andC44 may not be further partitioned, and C41 and C44 have data. It canthus be seen that, according to the method for picture decoding providedin the disclosure, it is only necessary to perform decoding processingon C11, C41 and C44 that have data to obtain corresponding CUs. SinceC41 and C44 have overlapping regions with C11 respectively, the decodermay refresh the CU corresponding to C11 according to the CUcorresponding to C41, and simultaneously refresh the CU corresponding toC11 according to the CU corresponding to C44 to finally obtain a decodedpicture corresponding to the CTU.

The embodiments of the application provide the method for picturedecoding, the decoder, and the storage medium. The decoder receives thebitstream data, and parses the bitstream data to obtain the CTUcorresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and all the nodescorresponding to the CTU are traversed until data of all CUscorresponding to the CTU is obtained. The decoded picture correspondingto the bitstream data is generated according to the all nodes and thedata of all CUs. It can be seen that, in the embodiments of theapplication, in a process of decoding a picture in a video, afterbitstream data is received and parsed to obtain a CTU, parsingprocessing may be performed on a node of each layer corresponding to theCTU to obtain a state parameter and flag parameter corresponding to thenode of this layer, then detection processing is performed on the nodeaccording to the state parameter and the flag parameter, and decodingprocessing is performed on nodes that have data, to obtain all CUscorresponding to the CTU to obtain a corresponding decoded picture.Since overlapping partitioning of CUs is supported during coding, if allthe CUs obtained by the decoder by decoding nodes that have data includeat least two regionally overlapping CUs, the decoder may performrefreshing processing on picture information corresponding to abackground CU according to picture information corresponding to arefreshing CU. Therefore, over-partitioning of video pictures may beavoided, unnecessary header information may be reduced, distributedrepeated representations of data with similar features in the sameregion may be avoided, and the coding efficiency may further beimproved.

In another embodiment of the application, the method for picturedecoding provided in the abovementioned embodiments is provided based onthe condition that overlapping of CUs is supported when the encoderperforms picture encoding. If overlapping of CUs is supported when theencoder performs picture encoding, detailed partitioning of the picutremay be avoided. Correspondingly, when the decoder decodes the videopicture, if the background pixel data corresponding to the background CUin data of all pixels and the refreshing pixel data corresponding to therefreshing CU have an overlapping region, the decoder may replace thepixel data of the corresponding region of the background CU according tothe pixel data of the refreshing CU, namely the background CU isrefreshed with the refreshing CU.

In summary, FIG. 18 is a schematic diagram of a method for pictureencoding according to embodiments of the application. As shown in FIG.18, the method for picture encoding performed by an encoder may includethe following operations.

In 301, a current coded picture is partitioned to obtain a CTUcorresponding to the current coded picture.

In the embodiments of the application, the coder may partition thecurrent coded picture at first, thereby obtaining the CTU correspondingto the current coded picture.

Furthermore, in the embodiments of the application, the encoder encodesmultiple frames of pictures in a video one by one during video encoding.The frame of picture under encoding at any moment may be called acurrent coded picture. The encoder, when encoding the current codedpicture in the video, needs to partition the current coded picture intoCTUs with the completely same size at first. For example, the encodermay partition the current coded picture to obtain CTUs with thecompletely same size of 64×64 pixels, namely CTUs formed by 64×64 pixelsare obtained.

It is to be noted that, in the embodiments of the application, theencoder may perform overlapping partitioning on the current codedpicture. Specifically, the encoder may perform overlapping partitioningon the current coded picture by MTT.

It is to be noted that, in the embodiments of the application, theencoder may set a preset refreshing coding mode and a normal coding moderespectively. The normal coding mode refers to a common coding mode thatdoes not allow overlapping between CTUs and overlapping between CUs. Bycontrast, the preset refreshing coding mode refers to a coding mode thatdoes not allow overlapping between CTUs. That is, overlapping betweenCTUs is not allowed in either the preset refreshing coding mode or thenormal coding mode.

Furthermore, in the embodiments of the application, the encoder mayselect to enable the preset refreshing coding mode or the normal codingmode during video encoding. From the encoder side, mode selection may beperformed on the preset refreshing coding mode and an original method byRate Distortion Optimization (RDO), and comparative judgment may beperformed in different layers. In an implementation process, a supportedrefreshed layer number, region number, etc., may also be selectedflexibly.

Furthermore, in the embodiments of the application, before the encoderpartitions the current coded picture to obtain the CTU corresponding tothe current coded picture, namely before operation 301, a coding modemay be switched into the preset refreshing coding mode at first.

It is to be noted that, in the embodiments of the application, theencoder, when partitioning the current coded picture, may perform CTUpartitioning according to a raster sequence, and the encoder may obtainmultiple CTUs by partitioning.

Furthermore, in the embodiments of the application, after the currentcoded picture is partitioned into the CTU, further partitioning may becontinued to be performed by MTT or another partition technology, andfinally, encoding may be performed by taking a CU as a unit.

In 302, the CTU is continued to be partitioned to obtain a background CUand refreshing CU corresponding to the CTU, the refreshing CU beingconfigured to cover a partial region of the background CU.

In the embodiments of the application, the encoder, after partitioningthe current coded picture to obtain the CTU corresponding to the currentcoded picture, may continue to partition the CTU to obtain thebackground CU and refreshing CU corresponding to the CTU. Both thebackground CU and the refreshing CU are CUs obtained by furtherpartitioning the CTU and configured for picture encoding.

It is to be noted that, in the embodiments of the application, therefreshing CU may be configured to cover the partial region of thebackground CU.

Furthermore, in the embodiments of the application, the encoder, afterobtaining the CTU, may continue to partition the CTU according to thepreset refreshing coding mode, thereby obtaining the background CU andrefreshing CU corresponding to the CTU. Specifically, the encoder mayextract pixel information in the CTU at first, and then partition theCTU according to the pixel information, so that the CTU may bepartitioned into the background CU and the refreshing CU. That is, theencoder may further partition the CTU into the background CU and therefreshing CU according to the pixel information in the CTU, therebyperforming picture encoding according to the background CU and therefreshing CU. The partial region of the background CU may be coveredand refreshed by the refreshing CU.

FIG. 18 is a first schematic diagram of non-overlapping partitioning.FIG. 19 is a second schematic diagram of non-overlapping partitioning.As shown in FIG. 18 and FIG. 19, according to an existing video codingmanner, for a detailed region with a content different from that ofanother region, for example, a content of region a is different fromthat of another region, the encoder, before partitioning the CTU, needsto perform detailed partitioning on the CTU according to the mannershown in FIG. 18 or FIG. 19 to achieve a relatively good video codingeffect because overlapping between CUs is not allowed. FIG. 20 is afirst schematic diagram of overlapping partitioning. FIG. 21 is a secondschematic diagram of overlapping partitioning. As shown in FIG. 20 andFIG. 21, for the same region a, since overlapping between CUs isallowed, the encoder, when partitioning the CTU, may specificallypartition the CTU into a refreshing CU and a background CU, and thencover a partial region of the background CU with the refreshing CU, toavoid excessively detailed partitioning and effectively reduce theamount of header information.

Furthermore, in the embodiments of the application, data of a pixeldomain needs to be transformed to a frequency domain by Discrete CosineTransform (DCT) and Discrete Sine Transform (DST), and then quantizationcoding is performed for transmission. For example, in a frame of currentpicture, a flat picture region with a relatively small amount of pixelinformation mainly includes low-frequency component, so that all energyafter the flat picture region is transformed is concentrated in theupper-left corner. That is, except a few values in the upper-leftcorner, all numerical values of other regions are substantially 0 duringpicture coding transmission. In such case, only the few values may betransmitted during transmission to represent pixel data of all regions.Correspondingly, if n pieces of data are required by coding andtransmitting the flat picture region, the flat picture region ispartitioned into four sub regions for coding transmission, and 4 npieces of non-zero data may be required to represent the region. Fromthe perspective of information, the same information is repeatedlyexpressed.

Furthermore, in the embodiments of the application, both MTTpartitioning and QTBT partitioning are implemented by performing QTpartitioning at first and then performing other types of partitioning oneach leaf node obtained by QT partitioning.

Furthermore, in the embodiments of the application, in the background CUand refreshing CU obtained by the encoder by partitioning the CTU, onebackground CU may be allowed to be refreshed by multiple refreshing CUs,or the refreshing CU is allowed to be refreshed with a refreshing CU ofa lower layer as a background CU. That is, in the embodiments of theapplication, the preset refreshing coding mode may allow multi-regionrefreshing and multilayer refreshing.

It is to be noted that, in the embodiments of the application, a methodthat the encoder partitions the CTU to obtain the background CU andrefreshing CU corresponding to the CTU may specifically include thefollowing operations.

In 302 a, the CTU is partitioned to obtain a jth background CU and jthrefreshing CU corresponding to a jth layer, j being an integer greaterthan 0.

In the embodiments of the application, the encoder, after partitioningthe current coded picture to obtain the CTU corresponding to the currentcoded picture, may partition the CTU according to MTT to obtain the jthbackground CU and jth refreshing CU corresponding to the jth layer, jbeing an integer greater than 0.

It is to be noted that, in the embodiments of the application, since thepreset refreshing coding mode may allow multilayer refreshing, theencoder may partition the CTU to obtain at least one layer of CUs.

In 302 b, the jth refreshing CU is partitioned to obtain a (j+1)thbackground CU and (j+1)th refreshing CU corresponding to a (j+1)thlayer.

In the embodiments of the application, the encoder, after partitioningthe CTU according to MTT to obtain the jth background CU and jthrefreshing CU corresponding to the jth layer, may continue to partitionthe jth refreshing CU according to MTT to obtain the (j+1)th backgroundCU and (j+1)th refreshing CU corresponding to the (j+1)th layer.

It is to be noted that, in the embodiments of the application, if theCTU includes multiple layers of CUs, the jth refreshing CU of the jthlayer may be continued to be partitioned into the (j+1)th background CUand (j+1)th refreshing CU corresponding to the (j+1)th layer. That is,in the background CU and refreshing CU obtained by the encoder bypartitioning the CTU, one background CU may be allowed to be refreshedby multiple refreshing CUs, or the refreshing CU is allowed to berefreshed with a refreshing CU of a lower layer as a background CU.

In 303, the CTU is encoded according to the background CU and therefreshing CU to generate bitstream data corresponding to the currentcoded picture.

In the embodiments of the application, the encoder, after partitioningthe CTU to obtain the background CU and refreshing CU corresponding tothe CTU, may encode the current coded picturee according to thebackground CU and the refreshing CU to generate the bitstream datacorresponding to the current coded picture.

Furthermore, in the embodiments of the application, the encoder, whenencoding the CTU according to the background CU and the refreshing CU,may encode the background CU at first, and then encode the refreshingCU, namely the encoder may encode the refreshing CU to generaterefreshing bitstream data only after encoding the background CU togenerate background bitstream data.

It is to be noted that, in the embodiments of the application, thebitstream data includes the background bitstream data and the refreshingbitstream data.

Furthermore, in the embodiments of the application, the encoder, afterencoding the current coded picture according to the background CU andthe refreshing CU to generate the bitstream data corresponding to thecurrent coded picture, may transmit the bitstream data. Specifically, inthe embodiments of the application, the encoder, when transmitting thebitstream data, may transmit the background bitstream data at first, andthen transmit the refreshing bitstream data, namely the encoder, whentransmitting the bitstream data, transmits the refreshing bitstream dataafter transmitting the background bitstream data.

It can thus be seen that, in the embodiments of the application, theencoder, when encoding the CTU according to the preset refreshing codingmode, encodes and transmits the large background CU at first, and thenencodes and transmits the refreshing CU. When decoding, correspondingly,the background CU is decoded at first, and then the refreshing CU isdecoded.

Furthermore, the coding manner disclosed in the application can beunderstood as a manner capable of implementing irregular shapepartitioning. In a process of encoding by taking a CU as a unit, CUs donot overlap, and instead, the encoder partitions a CTU into a backgroundCU and a refreshing CU. A partial region of the background CU is coveredwith the refreshing CU, an uncovered region is irregularly shaped, thispart is the region that the background CU needs to represent, and thecovered region is virtual extended data. QTBT can be considered as aspecial case of MTT, so that a similar method is implemented after MTTis introduced to VVC.

Furthermore, in the embodiments of the application, the encoder and thedecoder may also allow regional overlapping of CUs in prediction and/ortransformation links. Correspondingly, a CTU may include a correspondingbackground PU and refreshing PU, and may also include a correspondingbackground TU and refreshing TU.

Furthermore, in the embodiments of the application, the encoder mayimplement an irregular region partitioning method by block subtraction.

According to the method for picture encoding disclosed in theembodiments of the application, the encoder, when performing CUpartitioning on a current coded picture in a process of encoding anddecoding pictures in a video, may obtain a background CU and refreshingCU, that are partially regionally overlapped, through the presetrefreshing coding mode, and then perform encoding. Correspondingly, thedecoder, when decoding the current decoding picture according to apreset refreshing decoding, allows the refreshing CU to refresh a localregion of the background CU, so that over-partitioning over the videopicture may be avoided, unnecessary header information may be reduced,and the coding efficiency may further be improved.

Based on the abovementioned embodiments, in another embodiment of theapplication, FIG. 23 is a first composition structure diagram of adecoder according to embodiments of the application. As shown in FIG.23, the decoder 100 disclosed in the embodiments of the application mayinclude a receiving part 101, a parsing part 102, a detection part 103,an acquisition part 104, a generation part 105, a transmission part 106,and an enabling part 107.

The receiving part 101 is configured to receive bitstream data.

The parsing part 102 is configured to parse the bitstream data to obtaina CTU corresponding to the bitstream data.

The parsing part 102 is further configured to parse an ith node of anith layer corresponding to the CTU to obtain an ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.

The detection part 103 is configured to perform detection processing onthe ith node according to the ith state parameter and the ith flagparameter to obtain an ith detection result.

The acquisition part 104 is configured to acquire an (i+1)th node of an(i+1)th layer corresponding to the CTU according to the ith detectionresult.

The detection part 103 is further configured to continue to performdetection processing on the (i+1)th node and traverse all nodescorresponding to the CTU until data of all CUs corresponding to the CTUis obtained.

The generation part 105 is configured to generate a decoded picturecorresponding to the bitstream data according to the all nodes and thedata of all CUs.

Furthermore, in the embodiments of the application, the acquisition part104 is specifically configured to determine a leaf parametercorresponding to the ith node, the leaf parameter being configured todetermine whether to continue to partition the ith node, and obtain theith detection result according to the leaf parameter, the ith stateparameter, and the ith flag parameter.

Furthermore, in the embodiments of the application, the acquisition part104 is further specifically configured to, when the ith detection resultis that the node has data and is to be partitioned, acquire data of anith CU of the ith layer and perform segmentation processing on the ithnode to obtain the (i+1)th node of the (i+1)th layer corresponding tothe CTU; when the ith detection result is that the node has no data andis to be partitioned, perform partitioning processing on the ith node toobtain the (i+1)th node of the (i+1)th layer corresponding to the CTU;when the ith detection result is that the node has data and is not to bepartitioned, acquire data of an ith CU of the ith layer and end parsingprocessing of the ith node; and when the ith detection result is thatthe node has no data and is not to be segmented, end parsing processingof the ith node.

Furthermore, in the embodiments of the application, the generation part105 is specifically configured to perform decoding processing on thedata of all CUs based on the all nodes to obtain data of all pixelscorresponding to the CTU and generate the decoded picture correspondingto the bitstream data according to the data of all pixels.

Furthermore, in the embodiments of the application, the transmissionpart 106 is configured to, before detection processing is continued tobe performed on the (i+1)th node, transmit an (i+1)th state parameteraccording to the leaf parameter, the ith state parameter, and the ithflag parameter.

Furthermore, in the embodiments of the application, the transmissionpart 106 is specifically configured to determine, according to the leafparameter, the ith state parameter, and the ith flag parameter, whetherto perform state refreshing; responsive to determining to performdefault state refreshing, perform refreshing processing on the ith stateparameter to obtain the (i+1)th state parameter; and responsive todetermining not to perform state refreshing, determine the ith stateparameter as the (i+1)th state parameter.

Furthermore, in the embodiments of the application, the acquisition part104 is specifically configured to acquire an ith partitioning modecorresponding to the ith node and perform partitioning processing on theith node according to the ith partitioning mode to obtain the (i+1)thnode.

Furthermore, in the embodiments of the application, the acquisition part104 is further specifically configured to, when the ith node has dataand is not to be partitioned, decode the data of the ith CU to obtainith pixel data; when the ith node has data and is to be partitioned,decode the data of the ith CU to obtain ith background pixel data anddecode data of an (i+1)th CU to obtain ith refreshing pixel data toobtain the ith pixel data; and traverse the all nodes until the data ofall pixels is obtained.

Furthermore, in the embodiments of the application, the acquisition part104 is further specifically configured to perform refreshing processingon the ith background pixel data according to the ith refreshing pixeldata to obtain the ith pixel data and traverse the all nodes until thedecoded p[icture is obtained.

Furthermore, in the embodiment of the application, the acquisition part104 is further specifically configured to, when the ith node has dataand is to be partitioned, acquire data of an (i+1)th CU and decode thedata of the (i+1)th CU to obtain the ith refreshing pixel datacorresponding to the ith node; decode the data of the ith CU to obtainthe ith background pixel data and set the ith background pixel data as abackground of the ith refreshing pixel data to obtain the ith pixeldata; and traverse the all nodes until the data of all pixels isobtained.

Furthermore, in the embodiments of the application, the acquisition part104 is further specifically configured to, when the ith node has nodata, set the ith background pixel data to be null.

Furthermore, in the embodiments of the application, the generation part105 is further configured to, after detection processing is continued tobe performed on the (i+1)th node and the all nodes corresponding to theCTU are traversed until data of all CUs corresponding to the CTU isobtained, perform refreshing processing on data of an ith CU accordingto data of an (i+1)th CU.

Furthermore, in the embodiments of the application, the enabling part107 is configured to, after the bitstream data is received and thebitstream data is parsed to obtain the CTU corresponding to thebitstream data, enable a preset refreshing mode, the preset refreshingmode being configured to perform overlapping decoding on the CUs.

FIG. 24 is a second composition structure diagram of a decoder accordingto embodiments of the application. As shown in FIG. 24, the decoder 100disclosed in the embodiments of the application may also include aprocessor 108, a memory 109 storing instructions executable for theprocessor 108, a communication interface 110, and a bus 111 configuredto connect the processor 108, the memory 109 and the communicationinterface 110.

Furthermore, in the embodiments of the application, the processor 108 isconfigured to: receive bitstream data and parse the bitstream data toobtain a CTU corresponding to the bitstream data; parse an ith node ofan ith layer corresponding to the CTU to obtain an ith state parameterand ith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing;perform detection processing on the ith node according to the ith stateparameter and the ith flag parameter to obtain an ith detection result;acquire an (i+1)th node of an (i+1)th layer corresponding to the CTUaccording to the ith detection result; continue to perform detectionprocessing on the (i+1)th node and traverse all nodes corresponding tothe CTU until data of all CUs corresponding to the CTU is obtained; andgenerate a decoded picture corresponding to the bitstream data accordingto the all nodes and the data of all CUs.

In the embodiments of the application, the processor 108 may be at leastone of an Application Specific Integrated Circuit (ASIC), a DigitalSignal Processor (DSP), a Digital Signal Processing Device (DSPD), aProgrammable Logic Device (PLD), a Field Programmable Gate Array (FPGA),a Central Processing unit (CPU), a controller, a microcontroller, and amicroprocessor. It can be understood that, for different devices, otherelectronic components may be configured to realize functions of theprocessor, and no specific limits are made in the embodiment of theapplication. The memory 109 may be connected with the processor 108. Thememory 109 is configured to store an executable program code. Theprogram code includes a computer operation instruction. The memory 109may include a high-speed Random Access Memory (RAM), and may alsoinclude a non-volatile memory, for example, at least two disk memories.

In the embodiments of the application, the bus 111 is configured toconnect the communication interface 110, the processor 108, and thememory 109 and implement communications between these devices.

In the embodiments of the application, the memory 109 is configured tostore instructions and data.

In practical applications, the memory 109 may be a volatile memory suchas a RAM, or a non-volatile memory such as a Read-Only Memory (ROM), aflash memory, a Hard Disk Drive (HDD), or a Solid-State Drive (SSD), ora combination of the memories, and provides instructions and data forthe processor.

In addition, each function module in the embodiments may be integratedinto a processing unit, each unit may also exist independently, and twoor more than two units may also be integrated into a unit. Theintegrated unit may be implemented in a hardware form and may also beimplemented in form of software function module.

When implemented in form of a software function module and sold or usednot as an independent product, the integrated unit may be stored in acomputer-readable storage medium. Based on such an understanding, thetechnical solution of the embodiment substantially or parts makingcontributions to the conventional art or all or part of the technicalsolution may be embodied in form of software product, and the computersoftware product is stored in a storage medium, including a plurality ofinstructions configured to enable a computer device (which may be apersonal computer, a server, a network device or the like) or aprocessor to execute all or part of the steps of the method in theembodiment. The storage medium includes various media capable of storingprogram codes such as a U disk, a mobile hard disk, a ROM, a RAM, amagnetic disk, or an optical disk.

The embodiments of the application provide a decoder. The decoderreceives the bitstream data, and parses the bitstream data to obtain theCTU corresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and the all nodescorresponding to the CTU are traversed until the data of all CUscorresponding to the CTU is obtained. The decoded picture correspondingto the bitstream data is generated according to the all nodes and thedata of all CUs. It can be seen that, in the embodiments of theapplication, in a process of decoding a picture in a video, afterbitstream data is received and parsed to obtain a CTU, parsingprocessing may be performed on a node of each layer corresponding to theCTU to obtain a state parameter and flag parameter corresponding to thenode of this layer, then detection processing is performed on the nodeaccording to the state parameter and the flag parameter, and decodingprocessing is performed on a node that has data, to obtain all CUscorresponding to the CTU to obtain a corresponding decoded picture.Since overlapping partitioning of CUs is supported during coding, if allthe CUs obtained by the decoder by decoding nodes with data include atleast two regionally overlapping CUs, the decoder may perform refreshingprocessing on picture information corresponding to a background CUaccording to picture information corresponding to a refreshing CU.Therefore, over- partitioning of video pictures may be avoided,unnecessary header information may be reduced, distributed repeatedrepresentations of data with similar features in the same region may beavoided, and the coding efficiency may further be improved.

The embodiments of the application provide a computer-readable storagemedium having stored therein a computer program which is executed by aprocessor to implement the method as described in the abovementionedembodiments.

Specifically, a program instruction corresponding to a method forpicture decoding in the embodiments may be stored in a storage mediumsuch as an optical disk, a hard disk, and a U disk. When the programinstruction corresponding to the image decoding method in the storagemedium is read or executed by an electronic device, the followingoperations are included.

Bitstream data is received, and the bitstream data is parsed to obtain aCTU corresponding to the bitstream data.

An ith node of an ith layer corresponding to the CTU is parsed to obtainan ith state parameter and ith flag parameter corresponding to the ithnode, i being an integer greater than 0, the ith state parameter beingconfigured to determine whether the ith node supports refreshing, andthe ith flag parameter being configured to determine whether the ithnode enables refreshing.

Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain an ith detectionresult.

An (i+1)th node of an (i+1)th layer corresponding to the CTU is acquiredaccording to the ith detection result.

Detection processing is continued to be performed on the (i+1)th node,and all nodes corresponding to the CTU are traversed until data of allCUs corresponding to the CTU is obtained.

A decoded picture corresponding to the bitstream data is generatedaccording to the all nodes and the data of all CUs.

Those skilled in the art should know that the embodiment of theapplication may be provided as a method, a system or a computer programproduct. Therefore, the application may adopt a form of hardwareembodiment, software embodiment or combined software and hardwareembodiment. Moreover, the application may adopt a form of computerprogram product implemented on one or more computer-available storagemedia (including, but not limited to, a disk memory, an optical memoryand the like) including computer-available program codes.

The application is described with reference to implementation flowchartsand/or block diagrams of the method, device (system) and computerprogram product according to the embodiments of the application. It isto be understood that each flow and/or block in the flowcharts and/orthe block diagrams and combinations of the flows and/or blocks in theimplementation flowcharts and/or the block diagrams may be implementedby computer program instructions. These computer program instructionsmay be provided for a universal computer, a dedicated computer, anembedded processor or a processor of another programmable dataprocessing device to generate a machine, so that a device for realizinga function specified in one flow or multiple flows in the implementationflowcharts and/or one block or multiple blocks in the block diagrams isgenerated by the instructions executed through the computer or theprocessor of the other programmable data processing device.

These computer program instructions may also be stored in acomputer-readable memory capable of guiding the computer or the otherprogrammable data processing device to work in a specific manner, sothat a product including an instruction device may be generated by theinstructions stored in the computer-readable memory, the instructiondevice realizing the function specified in one flow or multiple flows inthe implementation flowcharts and/or one block or multiple blocks in theblock diagrams.

These computer program instructions may further be loaded onto thecomputer or the other programmable data processing device, so that aseries of operating steps are executed on the computer or the otherprogrammable data processing device to generate processing implementedby the computer, and steps for realizing the function specified in oneflow or multiple flows in the implementation flowcharts and/or one blockor multiple blocks in the block diagrams are provided by theinstructions executed on the computer or the other programmable dataprocessing device.

The above is only the preferred embodiments of the application and notintended to limit the scope of protection of the application.

INDUSTRIAL APPLICABILITY

The embodiments of the application provide a method for picturedecoding, a decoder, and a storage medium. The decoder receives thebitstream data, and parses the bitstream data to obtain the CTUcorresponding to the bitstream data. The ith node of the ith layercorresponding to the CTU is parsed to obtain the ith state parameter andith flag parameter corresponding to the ith node, i being an integergreater than 0, the ith state parameter being configured to determinewhether the ith node supports refreshing, and the ith flag parameterbeing configured to determine whether the ith node enables refreshing.Detection processing is performed on the ith node according to the ithstate parameter and the ith flag parameter to obtain the ith detectionresult. The (i+1)th node of the (i+1)th layer corresponding to the CTUis acquired according to the ith detection result. Detection processingis continued to be performed on the (i+1)th node, and all the nodescorresponding to the CTU are traversed until data of all CUscorresponding to the CTU is obtained. The decoded pictures correspondingto the bitstream data is generated according to the all nodes and thedata of all CUs. It can be seen that, in the embodiments of theapplication, in a process of decoding a picture in a video, afterbitstream data is received and parsed to obtain a CTU, parsingprocessing may be performed on a node of each layer corresponding to theCTU to obtain a state parameter and flag parameter corresponding to thenode of this layer, then detection processing is performed on the nodeaccording to the state parameter and the flag parameter, and decodingprocessing is performed on a node with data, to obtain all CUscorresponding to the CTU to obtain a corresponding decoded picture.Since overlapping partitioning of CUs is supported during coding, if allthe CUs obtained by the decoder by decoding nodes that have data includeat least two regionally overlapping CUs, the decoder may performrefreshing processing on picture information corresponding to abackground CU according to picture information corresponding to arefreshing CU. Therefore, over-partitioning of video pictures may beavoided, unnecessary header information may be reduced, distributedrepeated representations of data with similar features in the sameregion may be avoided, and the coding efficiency may further beimproved.

1. A method for picture decoding, comprising: receiving bitstream data,and parsing the bitstream data to obtain a Coding Tree Unit (CTU)corresponding to the bitstream data; parsing a node of a layercorresponding to the CTU to determine a state parameter and a flagparameter corresponding to the node, the state parameter beingconfigured to determine whether the node supports refreshing, and theflag parameter being configured to determine whether the node enablesrefreshing; determining a leaf parameter corresponding to the node, theleaf parameter being configured to determine whether to continue topartition the node; performing detection processing on the nodeaccording to the leaf parameter, the state parameter and the flagparameter to obtain a detection result; continuing to acquire a node ofa next layer corresponding to the CTU according to the detection result;continuing to perform detection processing on the node of the nextlayer, and obtaining data of all Coding Units (CUs) corresponding to theCTU; and generating a decoded picture corresponding to the bitstreamdata according to the node and the data of all CUs.
 2. The method ofclaim 1, wherein generating the decoded picture corresponding to thebitstream data according to the node and the data of all CUs comprises:performing decoding processing on the data of all CUs based on the nodeto obtain data of all pixels corresponding to the CTU; and generatingthe decoded picture corresponding to the bitstream data according to thedata of all pixels.
 3. The method of claim 1, before continuing toperform detection processing on the node of the next layer, furthercomprising: transmitting a state parameter of the next layer accordingto the leaf parameter, the state parameter, and the flag parameter. 4.The method of claim 3, wherein transmitting the state parameter of thenext layer according to the leaf parameter, the state parameter, and theflag parameter comprises: determining, according to the leaf parameter,the state parameter, and the flag parameter, whether to perform staterefreshing; responsive to determining to perform default staterefreshing, performing refreshing processing on the state parameter toobtain the state parameter of the next layer; and responsive todetermining not to perform state refreshing, determining the stateparameter as the state parameter of the next layer.
 5. The method ofclaim 1, after receiving the bitstream data and parsing the bitstreamdata to obtain the CTU corresponding to the bitstream data, furthercomprising: enabling a preset refreshing mode, the preset refreshingmode being configured to perform overlapping decoding on the CUs.
 6. Adecoder, comprising a processor and a memory storing instructionsexecutable by the processor, wherein when the instructions are executedby the processor, the processor is configured to: receive bitstreamdata; parse the bitstream data to obtain a Coding Tree Unit (CTU)corresponding to the bitstream data; parse a node of a layercorresponding to the CTU to determine a state parameter and a flagparameter corresponding to the node, the state parameter beingconfigured to determine whether the node supports refreshing, and theflag parameter being configured to determine whether the node enablesrefreshing; perform detection processing on the node according to a leafparameter, the state parameter and the flag parameter to obtain adetection result; continue to acquire a node of a next layercorresponding to the CTU according to the detection result; continue toperform detection processing on the node of the next layer, and obtaindata of all Coding Units (CUs) corresponding to the CTU; and generate adecoded picture corresponding to the bitstream data according to thenode and the data of all CUs.
 7. The decoder of claim 6, wherein theprocessor is specifically configured to perform decoding processing onthe data of all CUs based on the node to obtain data of all pixelscorresponding to the CTU and generate the decoded picture correspondingto the bitstream data according to the data of all pixels.
 8. Thedecoder of claim 6, wherein the processor is further configured to,before detection processing is continued to be performed on the node ofthe next layer, transmit a state parameter of the next layer accordingto the leaf parameter, the state parameter, and the flag parameter. 9.The decoder of claim 8, wherein the processor is specifically configuredto determine, according to the leaf parameter, the state parameter, andthe flag parameter, whether to perform state refreshing; responsive todetermining to perform default state refreshing, perform refreshingprocessing on the state parameter to obtain the state parameter of thenext layer; and responsive to determining not to perform staterefreshing, determine the state parameter as the state parameter of thenext layer.
 10. The decoder of claim 6, wherein the processor is furtherconfigured to, after the bitstream data is received and the bitstreamdata is parsed to obtain the CTU corresponding to the bitstream data,enable a preset refreshing mode, the preset refreshing mode beingconfigured to perform overlapping decoding on the CUs.
 11. Acomputer-readable storage medium having stored therein a computerprogram which is applied to a decoder and is executed by a processor toperform: receiving bitstream data, and parsing the bitstream data toobtain a Coding Tree Unit (CTU) corresponding to the bitstream data;parsing a node of a layer corresponding to the CTU to determine a stateparameter and a flag parameter corresponding to the node, the stateparameter being configured to determine whether the node supportsrefreshing, and the flag parameter being configured to determine whetherthe node enables refreshing; determining a leaf parameter correspondingto the node, the leaf parameter being configured to determine whether tocontinue to partition the node; performing detection processing on thenode according to the leaf parameter, the state parameter and the flagparameter to obtain a detection result; continuing to acquire a node ofa next layer corresponding to the CTU according to the detection result;continuing to perform detection processing on the node of the nextlayer, and obtaining data of all Coding Units (CUs) corresponding to theCTU; and generating a decoded picture corresponding to the bitstreamdata according to the node and the data of all CUs.
 12. Thecomputer-readable storage medium of claim 11, wherein generating thedecoded picture corresponding to the bitstream data according to thenode and the data of all CUs comprises: performing decoding processingon the data of all CUs based on the node to obtain data of all pixelscorresponding to the CTU; and generating the decoded picturecorresponding to the bitstream data according to the data of all pixels.13. The computer-readable storage medium of claim 11, wherein beforecontinuing to perform detection processing on the node of the nextlayer, the computer program is executed by the processor to furtherperform: transmitting a state parameter of the next layer according tothe leaf parameter, the state parameter, and the flag parameter.
 14. Thecomputer-readable storage medium of claim 13, wherein transmitting thestate parameter of the next layer according to the leaf parameter, thestate parameter, and the flag parameter comprises: determining,according to the leaf parameter, the state parameter, and the flagparameter, whether to perform state refreshing; responsive todetermining to perform default state refreshing, performing refreshingprocessing on the state parameter to obtain the state parameter of thenext layer; and responsive to determining not to perform staterefreshing, determining the state parameter as the state parameter ofthe next layer.
 15. The computer-readable storage medium of claim 11,after receiving the bitstream data and parsing the bitstream data toobtain the CTU corresponding to the bitstream data, the computer programis executed by the processor to further perform: enabling a presetrefreshing mode, the preset refreshing mode being configured to performoverlapping decoding on the CUs.